TY - JOUR
T1 - Role of orbitals in manganese oxides-ordering and fluctuation
AU - Maezono, R.
AU - Murakami, S.
AU - Nagaosa, N.
AU - Ishihara, S.
AU - Yamanaka, M.
AU - Lee, H. C.
N1 - Funding Information:
The authors would like to thank Y. Tokura, A. Millis, J. Ye, G. Kotliar, Q. Si, H. Kuwahara, S. Maekawa, H. Fukuyama, K. Miyake, T. Okuda, K. Yamamoto and Y. Endoh for valuable discussions. This work was supported by COE and Priority Areas Grants from the Ministry of Education, Science, Culture and Sports of Japan. Part of this work has been done in APCTP workshop and Aspen Center for Physics, and we acknowledge their hospitality.
PY - 1999/8/16
Y1 - 1999/8/16
N2 - We study the manganese oxides from the viewpoint of the strongly correlated doped Mott insulator. The magnetic ordering and the charge transport are governed by the orbital degrees of freedom, and their dimensionality is controlled by the anisotropic transfer integrals between the eg-orbitals. As x increases, the magnetic structure is predicted to change as A→F→A→C→G (F, ferromagnet; A, layered antiferromagnet; C, rod-type antiferromagnet; G, usual antiferromagnet), in agreement with experiments. Especially the orbital is aligned as dx2-y2 in the metallic A state, which explains the quasi 2D transport and no canting of the spin observed experimentally. Next we discuss the ferromagnetic state without the orbital ordering due to the quantum fluctuation. Here the interplay between the electron repulsion U and the Jahn-Teller electron-phonon interaction ELR is studied with a large d model. In addition to this strong correlation, we propose that the dynamical phase separation could explain the specific heat as well as the various anomalous physical properties, e.g. resistivity, photo-emission, etc.
AB - We study the manganese oxides from the viewpoint of the strongly correlated doped Mott insulator. The magnetic ordering and the charge transport are governed by the orbital degrees of freedom, and their dimensionality is controlled by the anisotropic transfer integrals between the eg-orbitals. As x increases, the magnetic structure is predicted to change as A→F→A→C→G (F, ferromagnet; A, layered antiferromagnet; C, rod-type antiferromagnet; G, usual antiferromagnet), in agreement with experiments. Especially the orbital is aligned as dx2-y2 in the metallic A state, which explains the quasi 2D transport and no canting of the spin observed experimentally. Next we discuss the ferromagnetic state without the orbital ordering due to the quantum fluctuation. Here the interplay between the electron repulsion U and the Jahn-Teller electron-phonon interaction ELR is studied with a large d model. In addition to this strong correlation, we propose that the dynamical phase separation could explain the specific heat as well as the various anomalous physical properties, e.g. resistivity, photo-emission, etc.
KW - Manganese oxides
KW - Mott insulator
KW - Orbitals
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U2 - 10.1016/S0921-5107(99)00069-0
DO - 10.1016/S0921-5107(99)00069-0
M3 - Conference article
AN - SCOPUS:0033618861
SN - 0921-5107
VL - 63
SP - 171
EP - 176
JO - Materials Science and Engineering B: Solid-State Materials for Advanced Technology
JF - Materials Science and Engineering B: Solid-State Materials for Advanced Technology
IS - 1-2
T2 - Proceedings of the 1998 7th NEC Symposium on Fundamental Approaches to New Material Phases: Phase Control in Spin-Charge-Orbital Complex Systems
Y2 - 11 October 1998 through 15 October 1998
ER -